Plumbing fitting



FIG. 1 is an elevational view taken from one side of a plumbing fitting showing my new design, the opposite side being a mirror image of the side shown;

FIG. 2 is an end elevational view thereof, taken from the left of FIG. 1; and

FIG. 3 is a top plan view thereof. 

The ornamental design for a plumbing fitting, substantially as shown and described. 